I have completed a pediatric residency and am in my third and final year of a research fellowship in which my major interest has been bilirubin metabolism. My ultimate goal is to become an independent investigator in the field of Pediatric Gastroenterology and Hepatology. During my fellowship, I have strengthened my background by completing coursework in biochemistry and nutrition. My laboratory research efforts have resulted in publications. Dr. Gerard Odell, my fellowship sponsor, has provided me with complete access to his laboratory and clinical experience. At this point in my career, I would like to further strengthen my future research capabilities by working in two basic science laboratories on projects which originated, and, ultimately (because of their nature), I will continue in our laboratory. The initial aspects of the proposed research will involve my working in the laboratories of two Ph.D. scientists, Dr. Frank Siegel (chemistry) and Dr. Henry Pitot (biochemistry). The protein chemistry and hepatocyte culture methodologies which they have offered to teach me will better equip me for independent investigation. Dr. Odell has offered me space in his laboratory in which to eventually return with my newly acquired skills. The projects I have proposed are important to clinical disturbances in bilirubin metabolism. Understanding and eventual correction of jj Gunn rat glucuronyl transferase deficiency (model for the human Crigler-Najjar syndrome) and breast-milk jaundice require knowledge of the methods related to protein chemistry and hepatocyte culture which I can learn from Drs. Siegel and Pitot. Since my ultimate goal is a full-time tenured faculty position with research time in the Pediatrics Department, Dr. Odell has offered complete access to his laboratory and also offered to coordinate my experience in the other labs by serving as my primary sponsor. This arrangement provides me with the advantages of being able to work with Ph.D. candidates and fellows in Dr. Siegel's protein chemistry laboratory and in Dr. Pitot's hepatocyte culture laboratory, yet still have independent lab space in the Department of Pediatrics, to which I eventually plan to return.